Nonostructured metal organic material electrode separators and methods therefor

ABSTRACT

Provided herein are nano structured electrode separators comprising metal organic materials capable of attaching to one or more electrodes and electrically insulating at least one electrode while allowing migration of ionic charge carriers through the nanostructured electrode separator. Methods of using such electrode separators include positioning a nanostructured electrode separator between two electrodes of an electrochemical cell.

CLAIM OF PRIORITY

This application is a divisional of U.S. application Ser. No.13/861,775, filed on Apr. 12, 2013, which claims the benefit of priorU.S. Provisional Application No. 61/625,973, filed on Apr. 18, 2012,which is incorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates to an electrode separator for use in a battery oran electrochemical cell.

BACKGROUND

Batteries and electrochemical cells can be used as sources of energy.Generally, batteries and electrochemical cells include a positiveelectrode, a negative electrode, a separator between the positiveelectrode and the negative electrode that prevents electrical contactbetween the two electrodes, and an electrolytic solution in contact withthe electrodes and separator that permits ion migration. Electrons flowfrom electrode to electrode via a conductor. The physical and chemicalproperties of the separator can affect the performance properties of thebattery or electrochemical cell.

SUMMARY

A separator for a battery or electrochemical cell can be ananostructured separator.

In one aspect, an electrode material includes an electrode substrate anda nanostructured separator on a surface of the electrode substrate.

In another aspect, an electrochemical cell comprising an electrodesubstrate, a nanostructured separator on a surface of the electrodesubstrate and a second electrode in contact with the nanostructuredseparator.

In another aspect, a method of forming an electrode material includesforming the nanostructured separator on a surface of the electrodesupport.

In another aspect, a method of forming an electrochemical cell includesforming the nanostructured separator on a surface of the electrodesupport and contacting the nanostructured separator with the secondelectrode.

In certain embodiments, the nanostructured separator can include ametal-organic material. The metal-organic material can be ametal-organic framework, a metal-organic polyhedron, or a coordinationpolymer.

In other embodiments, the nanostructured separator can be acovalent-organic framework.

In certain embodiments, the nanostructured separator can include a zincor lead coordination compound, for example, a zinc terephthalatemetal-organic framework or a lead-(4,4′-sulfonyldibenzoate)metal-organic framework. In other embodiments, the nanostructuredseparator can include a 2,5-thiophenediboronicacid covalent-organicframework.

In certain aspects, the electrode substrate can be a manganese oxide.

Advantageously, the nanostructured separator can allow for unprecedentedcontrol over ion conductivity and related performance characteristics ofbatteries or electrochemical cells.

Other aspects, embodiments, and features will be apparent from thefollowing description, the drawings, and the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a portion of a battery or anelectrochemical cell.

FIGS. 2A, 2B and 2C are diagrams illustrating a lattice structure thatcan be built to create a nanostructured separator.

FIGS. 3A and 3B are photographs of electrode pellet and nanostructuredseparator coated electrode pellet.

FIGS. 4A and 4B are micrograph images of electrode pellet andnanostructure separator coated electrode pellet.

FIGS. 5A and 5B are micrograph images of electrode pellet andnanostructured separator coated electrode pellet.

FIG. 6 is a graph depicting the X-ray powder diffraction pattern of thenanostructured separator on the electrode pellet.

FIG. 7 is a diagram depicting the X-ray crystal structure of thenanostructured separator on the electrode pellet.

FIGS. 8A and 8B are photographs of electrode pellet and nanostructuredseparator coated electrode pellet.

FIGS. 9A and 9B are micrograph images of electrode pellet andnanostructured separator coated electrode pellet.

FIG. 10 is a graph depicting the X-ray powder diffraction pattern of thenanostructured separator on the electrode pellet.

FIG. 11 is a diagram depicting the X-ray crystal structure of thenanostructured separator on the electrode pellet.

FIGS. 12A and 12B are micrograph images of the surface of an electrodepellet after pellet-press of a nanostructured separator.

FIG. 13 is a graph depicting the X-ray powder diffraction pattern of thenanostructured separator on the electrode pellet.

DETAILED DESCRIPTION

Referring to FIG. 1, a battery or electrochemical cell can include acathode, an anode and a separator between the cathode and anode. Thebattery or electrochemical cell can be contained within a suitablehousing (not shown).

The battery and electrochemical cell include a primary cell or anon-rechargeable battery or a secondary cell or rechargeable battery.Examples of a primary cell includes an alkaline battery, aluminumbattery, chromic acid cell, Clark cell, Daniell cell, dry cell, Earthbattery, Galvanic cell, Grove cell, Leclanché cell, lithium battery,lithium air battery, mercury battery, molten salt battery, nickeloxyhydroxide battery, oxyride battery, organic radical battery, paperbattery, Pulvermacher's chain reserve battery, silver-oxide battery,solid-state battery, voltaic pile, penny battery, trough battery,water-activated battery, Weston cell, zinc-air battery, zinc-carbonbattery, or zinc chloride battery. Examples of a secondary cell includesa flow battery, vanadium redox battery, zinc-bromine flow battery, fuelcell, lead-acid battery, deep cycle battery, VRLA battery, AGM battery,gel battery, lithium air battery, lithium-ion battery, Beltway battery,lithium ion polymer battery, lithium iron phosphate battery,lithium-sulfur battery, lithium-titanate battery, molten salt battery,nickel-cadmium battery, nickel-cadmium battery, vented cell type nickelhydrogen battery, nickel-iron battery, nickel metal hydride battery, lowself-discharge NiMH battery, nickel-zinc battery, organic radicalbattery, polymer-based battery, polysulfide bromide battery,potassium-ion battery, rechargeable alkaline battery, silicon airbattery, sodium-ion battery, sodium-sulfur battery, super iron battery,zinc-bromine flow battery, or zinc matrix battery.

The primary function of an electrode separator is to sever as anelectrical insulator between a positive electrode and a negativeelectrode (for example, a cathode and an anode, respectively) to preventmigration of electrons from electrode to electrode through the separatorwhile allowing for migration of ionic charge carriers through theseparator. The migration of ionic charge completes the electricalcircuit, permitting passage of current from positive electrode tonegative electrode in an electrochemical cell.

A nanostructured material, such as a metal-organic material (MOM),including a metal-organic framework (MOF), a metal-organic polyhedron(MOP), or a coordination polymer (CP), or a covalent-organic framework(COF) can serve as separator between electrodes in a battery orelectrochemical cell.

Metal-organic materials and coordination polymers refer to a largefamily of solids characterized by the nature of coordination bondingbetween metal ions and organic linkers. The metal ions can includealkali metals, rare-earth metals, transition metals, lanthanides, orpost-transition metals. Organic linkers can include any organic moleculecapable of formation of coordination or ionic bond to metal ions.Organic linkers generally possess functional groups like carboxylicacids, amines, azoles, oxazoles, thiols, thiazoles and other heteroatomgroups capable of bonding to a metal ion. MOMs and CPs can exhibitvarious structures ranging from discrete supermolecules (known also asmetal-organic polyhedra, MOPs) to chains to layers and sheets to 3Dstructures. MOMs and CPs can exhibit permanent porosity as indicated byreversible gas sorption isotherms and/or reversible guest exchangebehavior.

Covalent-organic frameworks refer to a large family of solidscharacterized by the nature of covalent bonding between organicmonomers. The organic monomers can contain metal ions include alkalimetals, rare-earth metals, transition metals, lanthanides, orpost-transition metals. Organic monomers include any organic moleculecapable of formation of covalent bonds to the same molecule to formhomo-polymer or other type of molecules to form hetero-polymer. Organicmonomers generally possess functional groups like carboxylic acids,amines, azoles, oxazoles, thiols, thiazoles, terminal alkynes,halogenated aromatics like iodo/bromo benzenes, boronic acids,aldehydes, amides, acyl halides or other functional groups. COFs canexhibit various structures ranging from discrete supermolecules tochains to layers and sheets to 3D structures. COFs can exhibit permanentporosity as indicated by reversible gas sorption isotherms and/orreversible guest exchange behavior.

A nanostructured separator is a separator that has nanometer orsub-nanometer sized features that provide the nanostructured separatorwith particular properties that can enhance the performance of a batteryor electrochemical cell. In general, the nanostructured separator can bebuilt from a framework of molecular structures depicted in FIGS. 2A, 2Band 2C, and combinations thereof. In these structures, there is apolyvalent core, which can be a metal ion, atom, or other moiety capableof bonding with 2, 3, 4, 5, 7, 8, 9, 10, 11 or 12 bridging groups toform a scaffold. The bonds can be covalent bonds, ionic bonds or dativebonds, or combinations thereof. The scaffold or regions thereof can beone-, two- or three-dimensional in structure and can consist of thevarious bonding motifs shown in FIGS. 2A, 2B and 2C.

The polyvalent core can be carbon, silicon, a di-, tri-, or quadravalentorganic moiety (for example, carbon atom, ethylene group, aryl group,and the like), or a metal ions of one or more main group element ortransition metal including ions of Li, Na, K, Cs, Mg, Ca, Sr, Ba, Sc, Y,Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh, Jr, Ni,Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Ti, Si, Ge, Sn, Pb, As, Sb,or Bi.

The bridging group can be a polydentate group, for example, a C2-12hydrocarbon chain optionally containing at least one double bond, atleast one triple bond, or at least one double bond and one triple bondand optionally interrupted by at least one —O—, —N(Rc)-, or S, or C3-16cyclic group, optionally aromatic and optionally heterocyclic, thebriding group being optionally substituted with alkyl, alkenyl, alkynyl,alkoxy, hydroxyl, hydroxylalkyl, halo, haloalkyl, amino, carboxyl,amido, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 alkoxy, nitro,cyano, C3-5 cycloalkyl, 3-5 membered heterocycloalkyl, monocyclic aryl,5-6 membered heteroaryl, C1-4 alkylcarbonyloxy, C1-4 alkyloxycarbonyl,C1-4 alkylcarbonyl, or formyl group, which is capable of bonding to 2,3, 4, 5, or 6, or more, of the polyvalent cores. Rc can be H or C1-4alkyl.

The nanostructured separator can have a permanent porosity, high surfacearea and appropriate chemical, thermal and physical stability suitableof use in a battery or electrochemical cell. In other embodiments,enclathrated or encapsulated guest molecules or ions can undergo guestexchange with other molecular or ionic species in the nanostructuredseparator to alter properties of the separator. The surface area may bedetermined by using the BET method (“BET surface area”). This refers tothe Brunauer, Emmett and Teller (BET) method for surface areadetermination, which utilizes the isothermal adsorption of nitrogen tomeasure total surface area of a material. Another method uses theLangmuir model. Thermal stability can be determined using differentialscanning calorimetry (DSC), differential thermal analysis (DTA), orthermogravimetric analysis (TGA). Porosity can be determined byporosimitry measurements.

The nanostructured separator can include designable and tunable poresizes, pore distribution and pore shape. In another embodiment, thenanostructured separator can include designable and tunable porefunctionality. For example, accessible voids inside the porous materialcan incorporate a variety of guest molecules, ions or gases of desirablefunctionality for the nanostructured separator. In another embodiment,the nanostructured separator can include a designable and tunablecomposition of the organic/inorganic parts of the separator, which canprovide control and enhancement in the design and selection of suitablematerial specific electrochemical systems. In another embodiment, thenanostructured separator can have a neutral or charged backbone(cationic or anionic) where in charged backbone the presence ofencapsulated/enclathrated counterions can provide control andenhancement in the design and selection of suitable material specificelectrochemical systems. The high crystallinity of the nanostructuredseparator enables accurate structural characterization and control ofdesirable properties including ion conductivity, ion exchange, or voiddimensions.

For example, the nanostructured separator can havechannels/cages/windows within a relatively wide range in diameter (0.5˜5nm), or with a wide range of surface area (few m²/g to several hundredm²/g. The nanostructured separator can demonstrate good thermalstability (usually stable to 200° C.˜300° C.) and chemical stability(stable against structural disintegration in neutral, acidic,or basicsolutions.

The nanostructured separator should be thick enough to reduce oreliminate shorting between the positive electrode and the negativeelectrode by impedance or by preventing electrode dendrite formation. Itis important that the nanostructured separator also allow for facile ionmigration between the positive electrode and the negative electrode. Forexample, the pore size in the nanostructured separator must be smallenough to avoid formation of dendrites through the membrane, but largeenough to permit ion migration. The impedance of the nanostructuredseparator should be high enough to prevent electrical shorting betweenthe positive electrode and the negative electrode while optimizing theefficiency of the battery or electrochemical cell. For example, theaverage pore diameter of the nanostructured separator can be less than20 nm, less than 10 nm, less than 5 nm, less than 1 nm, or greater than0.5 nm. The average thickness of the nanostructured separator can beless than 100 microns, less than 50 microns, less than 10 microns, lessthan 1 micron, less than 500 nm, less than 200 nm, less than 100 nm,less than 50 nm, less than 40 nm, less than 30 nm, less than 20 nm, lessthan 10 nm, less than 5 nm, less than 1 nm, or greater than 0.5 nm.

Materials appropriate for use for the nanostructured separator caninclude a metal-organic material (MOM), including a metal-organicframework (MOF), a metal-organic polyhedron (MOP), or a coordinationpolymer (CP), or a covalent-organic framework (COF) that issubstantially inert to the electrolytic solution and capable of reducingor eliminating electron transfer between electrodes. The nanostructuredseparator can include wettable material coatings, polymers, gels, orfillers such as, for example, inorganic particles, biopolymers,polysaccharides, cellulose, dixtrans, cyclodextrins, silicates, ornanoparticles.

Examples of possibly suitable nanostructured materials include themetal-organic framework materials described, for example, in U.S. Pat.Nos. 8,123,834, 8,034,952, 7,880,026, 7,279,517, 6,929,679, 6,893,564,and 6,624,318, each of which is incorporated by reference in itsentirety. The design of pores in metal organic framework materials isdescribed, for example, in U.S. Pat. Nos. 7,196,210, and 6,930,193, eachof which is incorporated by reference in its entirety. Other examples ofpossibly suitable nanostructured materials are described, for example,in T. Kundu, et al., ChemComm 2012, DOI: 10.1039/c2cc31135f, which isincorporated by reference in its entirety.

The MOFs described in U.S. Pat. No.: 8,123,834 include Zn-MOF1, Zn-MOF2,Zn-MOF3, Zn-MOF4, ZnMOFS, Cu-MOF1, Cu-MOF2, Tb-MOF1, Tb-MOF2, Cd-MOF1,Cd-MOF2, CdMOF3, Co-MOF1, Co-MOF2, Zn-MOF6, MOF-5,Cu(4,4′-bpy)_(1.5)NO₃(H₂O)_(1.25), IRMOF2,[Cu₃(TMA)₂]n,[Cu(OH)—(C₅H₄NCO₂], MOF-38, Ag(4,4′-bpy)NO3, IRMO3 and IRMOF7, amongothers.

The MOFs described in U.S. Pat. No.: 8,034,952 include supramolecularassemblies comprising a 1:8 ratio of a supermolecular polyhedralbuilding block and a triangular molecular building block, which form a(3,24)-connected rht net, among others. The supermolecular polyhedralbuilding block has points of extension corresponding to the vertices ofa rhombicuboctahedron (and other regular polyhedra that have 24 verticesand the edge skeleton shared by small rhombihexahedron, smallcubicuboctahedron, and rhombicuboctahedron) for linking thesupermolecular polyhedral building block to the triangular buildingblocks. In the assembly, an individual supermolecular polyhedralbuilding block is linked to twenty-four different triangular buildingblocks and an individual triangular building block is linked to threedifferent supermolecular polyhedral building blocks with the linkagescomprising covalent bonds, coordinate covalent bonds, noncovalent bonds,or a combination thereof.

The MOFs described in U.S. Pat. No.: 7,880,026 include IRMOF-1, IRMOF-2,IRMOF-3, Zn-MOF-1, Zn-MOF-2, Zn-MOF-3, Zn-MOF-4, Zn-MOF-5, Cu-MOF-1,Cu-MOF-2, Tb-MOF-1, Tb-MOF-2, Cd-MOF-1, Cd-MOF-2, Cd-MOF-3, Co-MOF-1,Co-MOF-2, Zn-MOF-6, MOF-5, Cu(4,4′-bpy)_(1.5)NO₃(H₂O)_(1.25),[Cu₃(TMA)₂]_(n), [Cu(OH)—(C₅H₄NCO₂]_(n), MOF-38, Ag(4,4′-bpy)NO₃, andIRMOF-7, among others.

Referring again to FIG. 2, the battery or electrochemical cell caninclude three layers. The first layer can be a substrate, and can be oneelectrode of the battery or the electrochemical cell. The nanostructuredseparator can be grown on a substrate, such as a first electrode of abattery or electrochemical cell. For example, the nanostructuredseparator can be grown on an anode material. The substrate can be anysolid support, for example, a porous, conductor, semi-conductor,magnetic, metallic, non-metallic, photoactive, polymer, or heatresponsive material. The substrate can be conducting, semiconducting orinsulating. The substrate can be quartz, diamond, silica, alumina, ametal oxide, a metal hydroxide, a metal in elemental state or othersuitable material. The substrate can be amorphous, polycrystalline, or asingle crystal. The substrate surface in contact with the nanostructuredseparator can have a polished, rough, patterned, or functionalizedsurface, for example, with surface-active molecules (SAMs). Eachelectrode, independently, can include a metal, metal oxide, metal salt,metal complex, metal nanoparticle, molten salt or gas.

The second layer can be a nanostructured separator. The nanostructuredseparator can be any MOF, MOP, CP, or COF of desirable structure orfunctionality. For example, the nanostructured separator can benon-porous, microporous, or mesoporous. The nanostructured separator canform chains, sheets, or a 3D polymer or crystalline network. Inaddition, the nanostructured separator can be neutral, anionic, orcationic and can include different counterions, combining any one ormore metal, transition metal, lanthanides, alkaloids, rare-earth metals,chalcogenides, and one or more organic molecule as linker. In certainembodiments, the nanostructured separators can include accessible voidsinside the structure, which can be empty or occupied by guest moleculesthat can be solvent, organic substance, counterions, ionic species,gases, or other species. The dimension and chemical composition of thenanostructured separator along with the nature of optional enclosedguest molecules orions can provide control over ion migrationcharacteristics through the separator, thus enabling enhancement and/orcontrol of the battery orelectrochemical cell performance.

The third layer can be the second electrode, or cathode, of the batteryor electrochemical cell. The second electrode can be any solid support,for example, a porous, conductor, semi-conductor, magnetic, metallic,non-metallic, photoactive, polymer, or heat responsive material. Thesecond electrode can be conducting, semiconducting or insulating. Thesecond electrode can be quartz, diamond, silica, alumina, a metal oxide,a metal hydroxide, a metal salt, a metal in elemental state, metalloid,or other suitable material. The second electrode can be amorphous,polycrystalline, or a single crystal. The second electrode surface incontact with the nanostructured separator can have a polished, rough,patterned, or functionalized surface, for example, with surface-activemolecules (SAMs). The second electrode can be metals, metal oxides,metal salts, metal complexes, metalloid, metal or metalloidnanoparticles, molten salts or gases. The second electrode can beelectrochemically complementary to the first electrode. For example, thefirst electrode can be a manganese oxide and the second electrode can belithium.

Each of the anode or cathode can be fabricated through a variety oftechniques such as pressing from powder, chemical or electrical platingor deposition, spray deposition, monolith, sputtering, or casting. Thenanostructured separator, such as MOM, CP, or COF can be deposited onone or more of the anode or cathode through solvothermal syntheses,spraying, dry grinding, vapor deposition, pellets pressing, or printing.The nanostructured separator can be deposited as phase pure material oras a mixture with other ingredients in the form of composite material.Alternatively, the nanostructured separator can include a MOM, CP or COFsupported inside cavities or channels of a gel, a sol-gel, a porousinorganic support, or an organic polymer.

Examples of fabricating a nanostructured separator follow. In oneexample, a thin film of the nanostructured separator can be formed on apressed pellet of manganese oxide, which can be used as an electrode inbattery or electrochemical cell.

Example 1

180 mg of finely grinded MnO₂ was pressed at 15,000 lb/inch² to preparethe solid support. A mixture of terephthalic acid (0.5 mmol, 83 mg) andZn(NO₃)₂.6H2O (1 mmol, 297 mg) was prepared and dissolved inN,N′-diethylformamide (5 mL) and 1 mL of this mixture added to thesupport in a closed vial, heated at 105° C. for 12 h to result in ahomogenous coverage of the substrate by the MOF.

FIGS. 3A and 3B represent photographs of MnO₂ press-pellet as substrate(FIG. 3A) and after coating by Zn-terephthalate MOF (FIG. 3B). FIGS. 4Aand 4B represent SEM images of the surface of the MnO₂ support (FIG. 4A)and after growth of the MOF film on the support (FIG. 4B). FIGS. 5A and5B represent SEM images showing the cross section of the MOF thin filmon top of the MnO₂ substrate at two different magnifications. Theaverage cross section of the MOF thin film was 60 microns.

Referring to FIG. 6, the X-ray powder diffraction pattern of theZn-terephthalate MOF film grown on the MnO₂ substrate. FIG. 7 representsthe X-ray single crystal structure of the Zn-terephthalate MOF filmgrown on the MnO₂ substrate. The disordered parts of the framework,hydrogen atoms and disordered guest solvent molecules are omitted forclarity.

Example 2

180 mg of finely grinded MnO₂ was pressed at 15,000 lb/inch² to preparethe solid support. A mixture of 4,4′-sulfonyldibenzoic acid (0.1 mmol,30 mg) and Pb(NO₃)₂ (0.1 mmol, 33 mg) was prepared and dissolved inN,N′-dimethylformamide (2 mL) and this mixture added to the support in aclosed vial, heated at 115° C. for 12 h to result in a homogenouscoverage of the substrate by the Pb-(4,4′-sulfonyldibenzoate) MOF.

FIGS. 8A and 8B represent photographs of MnO₂ press-pellet as substrate(FIG. 8A) and after coating by Pb-(4,4′-sulfonyldibenzoate) MOF (FIG.8B). FIGS. 9A and 9B represent SEM images of the surface of the MnO₂support (FIG. 9A) and after growth of the Pb-(4,4′-sulfonyldibenzoate)MOF film on the support (FIG. 9B).

Referring to FIG. 10, the X-ray powder diffraction pattern of thePb-(4,4′-sulfonyldibenzoate) MOF film grown on the MnO₂ substrate. FIG.11 represents the X-ray single crystal structure of thePb-(4,4′-sulfonyldibenzoate) MOF film grown on the MnO₂ substrate. Thedisordered parts of the framework, hydrogen atoms and disordered guestsolvent molecules are omitted for clarity

Example 3

A solution of 2,5-thiophenediboronicacid (70 mg) in tetrahydrofuran (2mL) and toluene (2 mL) was prepared and heated in closed vial at 105° C.for 24 h. The resulting finely crystalline solid was air dried andspread on the surface of gently pressed MnO₂ powder (180 mg) inside thepellet-press. The solids were pressed together at 15,000 lb for 5minutes to result in uniformly covered surface by the COF. FIGS. 12A and12B represent SEM images of the surface of the MnO₂ support afterpellet-press of microcrystalline COF into a thin film (FIG. 12A), andside view indicating average cross section of 80 microns (FIG. 12B).Referring to FIG. 13, the X-ray powder diffraction pattern of the2,5-thiophenediboronicacid COF film grown on the MnO₂ substrate.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Otherembodiments are within the scope of the following claims.

1-24. (canceled)
 25. A nanostructured electrode separator, consistingessentially of: a covalent organic framework, wherein the nanostructuredelectrode separator is a phase-pure material.
 26. The separator of claim25, wherein the nanostructured electrode separator serves as anelectrical insulator between a first electrode and a second electrode.27. The separator of claim 25, wherein the nanostructured electrodeseparator is attached to a surface of a first electrode or a secondelectrode.
 28. The separator of claim 27, wherein the first electrode orsecond electrode is a manganese oxide electrode.
 29. The separator orclaim 25, wherein the nanostructured electrode separator includes a2,5-thiophenediboronic acid covalent organic framework.
 30. Theseparator of claim 25, wherein the nanostructured electrode separatorhas an average pore diameter of less than about 20 nm and greater thanabout 10 nm.
 31. An electrochemical cell, comprising: a first electrode;a nanostructured electrode separator attached to a surface of the firstelectrode and consisting essentially of a covalent organic framework;and a second electrode electrically insulated from the first electrode.32. The cell of claim 31, wherein the nanostructured electrode separatoris a phase-pure material.
 33. The cell of claim 31, wherein thenanostructured electrode separator includes a 2,5-thiophenediboronicacid covalent organic framework.
 34. The cell of claim 31, wherein oneof the first electrode and second electrode is a manganese oxideelectrode.
 35. The cell of claim 31, wherein the nanostructuredelectrode separator has an average pore diameter less than about 20 nmand greater than about 10 nm.
 36. A method of forming an electrochemicalcell, comprising: depositing a nanostructured electrode separator on afirst electrode, wherein the nanostructured electrode separator consistsessentially of a metal organic material or covalent organic framework;and contacting the nanostructured electrode separator with a secondelectrode.
 37. The method of claim 36, wherein the metal organicmaterial is a metal-organic framework.
 38. The method of claim 36,wherein the metal organic material is a metal-organic polyhedron. 39.The method of claim 36, wherein the metal organic material is acoordination polymer.
 40. The method of claim 36, wherein thenanostructured separator includes a zinc or lead coordination compound.41. The method of claim 36, wherein the nanostructured separatorincludes a zinc terephthalate metal-organic framework.
 42. The method ofclaim 36, wherein the nanostructured separator includes alead-(4,4′-sulfonyldibenzoate) metal-organic framework.
 43. The methodof claim 36, where in the nanostructured separator includes a2,5-thiophenediboronic acid covalent-organic framework.
 44. The methodof claim 36, wherein the metal organic material comprises Zn-MOF1,Zn-MOF2, Zn-MOF3, Zn-MOF4, ZnMOF5, Cu-MOF1, Cu-MOF2, Tb-MOF1, Tb-MOF2,Cd-MOF1, Cd-MOF2, CdMOF3, Co-MOF1, Co-MOF2, Zn-MOF6, MOF-5,Cu(4,4′-bpy)1.5NO3(H2O)1.25, [Cu3(TMA)2]n, [Cu(OH)—(C5H4NC2], MOF-38,Ag(4,4′-bpy)NO3, IRMOF-1, IRMOF-2 and IRMOF-3, IRMOF3, IRMOF7, or asupramolecular assembly comprising a 1:8 ratio of a supermolecularpolyhedral building blocks and a triangular molecular building blockswhich form a (3,24)-connected rht net.